"My husband and I are only concerned about Josh" and the two others, she said.

Switzerland has represented U.S. interests in Iran since American diplomats were taken hostage at the embassy in Tehran 30 years ago, and the State Department has said it asked the country to intervene in this case.

Iran's state owned Arabic-language al-Alam TV station cited a "well-informed source" in the Interior Ministry as saying the three American hikers were detained Friday.

The Americans had traveled with a companion to Turkey, then entered Iraq on Tuesday through the border crossing at Zakho and traveled to Sulaymaniya, according to the Kurdish regional government. On Thursday, the three took a taxi to the resort town of Ahmed Awaa, it added.

The regional government's statement said the three got lost during an excursion and were detained by Iranian authorities at the border.

A Kurdish security official says the three contacted a fourth member of their group shortly before their capture to say they had entered Iran by mistake and were surrounded by troops.

The fourth traveler, Shon Meckfessel, stayed behind because he had a cold, according to his grandmother, Irene Meckfessel of Carmichael (Sacramento County). She said he called her Saturday from the American Embassy in Baghdad.

Meckfessel was studying Arabic, his grandmother said: "He's very much interested in people and languages and he's working on a Ph.D. in linguistics."